Recently, many passenger seats on an aircraft are movable, and are equipped with functions such as a reclining function. Consumption of components constituting movable portions is inevitable, since the components are moved in sliding motion, and load on the components increases and decreases. In many cases, the seats on the aircraft are used continuously for a few years to even over ten years by subjecting the seats to maintenance operations, and the consumed parts are often replaced. Normal maintenance is performed while an airframe is landed at an airport during flight operation, so that the time that can be used for replacing the components is short, and the replacement operation must be performed within a limited narrow space within a cabin of the aircraft.
A prior art passenger seat of an aircraft proposes providing a movable portion retained in a state sandwiched between spreaders, serving as a pair of frame bodies arranged on both sides of the seat, and that moves within a groove formed on the spreaders, to recline or change positions of the seat (Patent Literature 1).